knife /ˈnaɪ̯f/noun 3verb 5forms 5phrases 3 noun3 •a tool for cutting, with a handle and a flat blade, which is usually made of metal and sharpened along one edgeHe was looking for a knife to chop some steak. •A weapon designed with the aforementioned specifications intended for slashing or stabbing but too short to be called a sword; a dagger. •Any blade-like part in a tool or a machine designed for cutting, such as that of a chipper. verb5 •To cut with a knife. •To use a knife to injure or kill by stabbing, slashing, or otherwise using the sharp edge of the knife as a weapon.She was repeatedly knifed in the chest. •To cut through as if with a knife.The boat knifed through the water. •To betray, especially in the context of a political slate. •To positively ignore, especially in order to denigrate; compare cut. formsknifed · knifing · knifes · knifes · knives Phrases with knife catch a falling knifeTo buy a financial instrument whose price is falling rapidly. knife upTo cut up or carve up with a knife. stick the knife inTo say or do something deliberately and unnecessarily malicious.